Air-brake apparatus.



H. M. P. MURPHY.

AIR BRAKE APPARATUS.

APPLICATION FILED MARiz. 1908.

Patented Feb.16,1o9.'

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H. M. P. MURPHY.

' AIR BRAKE APPARATUS.

APPLICATION FILED MAR. 2, 190B.

Patented Feb. 16, 1909 3 SHEETS-SHEET 2.

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MPLIUASLION FILED MAR. 2, 1908. Patented Feb. 16 1909- i 3 SHEETS-.SHEET3.

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HOWARD M. P. MURPHY, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR OF ONE-FOURTHTO LEE H. BOWMAN, OF MUNHALL, PENNSYLVANIA, AND ONE-EIGHTH TO JOSEPH M.FLAN- NERY, OF PITTSBURG. PENNSYLVANIA.

AIR-BRAKE APPARATUS.

To all whom it may concern.'

Be it known that I, Howano M. P. MUR- PHY, a resident of Pittsburg, inthe county of Allegheny and State of Pennsylvania,

have invented certain new and useful lmprovements in Air-BrakeApparatus; and l do hereby declare the following to be a ull, clear, andexact description of the invention, such as will enable others skilledin the art l0 to which it appertains to make and use the same.

This invention relates to improvements in air brake apparatus, and moreparticularly to improved means for controlling the operation of thebrakesV-the object of the in'- vention being to provide a simple valvemechanism capable of operating accurately to apply, release, hold andmaintain any desired amount ot pressure in the brake cylinder, saidvalve mechanism acting in response to variations of pressure in acontrolling chamber, said variations in pressure being under the controlof the operator with the 'use of a manually operated valve which may beso constructed that a higher brake cylinder pressure can be obtained ineases oi emergency than is necessary in the average service operation.

, A further object is to so construct the mechanism that a denitepressure can be maintained in the brake cylinder for any desired lengthof time, notwithstanding` any leakage which might occur from the brakecylinder.

lVith these objects in view, the invention consists in certain novelfeatures of construction and combinations of parts as hereinafter setforth and pointed out in the claims.

In the accompanying drawings, Figure 1 isa sectional view, partly inelevation, illustrating my improvements; Fig. 2 is a top view of therotary hand operated controlling` valve.' Fig. 3 is a top view ot theseat for said rotary valve. Figs. 4t, 5 and G are sectional. viewsillustrating the different positions of said controlling valve, andFigs. 7

8 and 9 are views illustrating modifications.

1 represents a valve casing secured by suitable means to the head of abrake cylinder 1a. This casing is provided in its upper portion with amain or controlling chamber 2;

in its intermediate portion with a chamber 3 and in its lower portionwith a chamber lt.

A sleeve or bushing 5 passes through an IAD Ofl

Speccaton of Letters Patent.

Application led March 2, 1908.

Patented Feb. 16, 1909.

Serial No. 418,864.

opening in the division wall between the chambers 2 and 3 and isprovided between its ends with an annular chamber 6. A seat is providedat the upper end of the sleeve or bushing 5 for a valve 7 on a rod 8which passes through said sleeve, terminating at its upper end withinthe chamber 2 and extending downwardly through the chamber 3. A piston 9located within the chamber 2, is secured to the upper portion of the rod8 and to the lower portion olih said rod, within the chamber 3, a piston10 is secured. A stem 11 in line with but disconnected from the rod S,passes through a sleeve or bushing 12 which extends from the chamber 3to the chamber l. The lower portion of the sleeve 12 is made with asmall internal chamber 13, the lower end ol which is adapted to beclosed by a valve 14: fixed to the lower end of the stem 11, and aspring 15 tends to press this valve toward its seat.

A duct 16 comn'nlnicates at its upper end with the main or controllingchamber 2 below the piston 9 therein and at its other end, this ductreceives tluid from a pipe 17, the latter being connected with asuitable source ot' supply, such a main air reservoir, and thisconnection of the pipe 1T with the air reservoir or other source ofsupply may, if desired, be made through the medium of a suitablereducing valve mechanism.

A duct 19 communicates at one end with the upper portion of the chamber2 above the piston 9 and at its other end, this duct is adapted tocommunicate with a pipe 2O which closely resembles in its functions, thebrake pipe l or train line pipe of air brake systems now in use.

A duct 21 communicates at one end with the brake cylinder 1a and at itsother end with the small chamber 6 in the sleeve or bushing 5, saidchamber G being also connected, through the medium of a duct 22 with thechamber it at the lower end of lthe casing. From the duct 22, a shortduct or passage 23 extends to the chamber 3 above the piston 10 therein.A duct 24, open to the atmosphere communicates with the chamber 13 inthe sleeve or bushing 12, and a duct open at one end, communicates atits other end with the chamber 3 below the piston 10 therein.

It is apparent that when the parts are in the positions shown in thedrawings, air can escape from the brake cylinder through the ducts 21and 22 to the chamber 4 and from the latter (the valve 14 being open)through the chamber 13 in bushing 12 and the duct 24 to the atmosphere.It is also readily to be seen that when the valve 14 is closed and thevalve 7 open, Huid under pressure, entering the chamber 2, by the duct16 and pipe 17, will flow from said chamber 2 to the small chamber 6 andfrom the latter, through the duct 21 to the brake cylinder 1a.

Now it will be observed that the mechanism comprises two pistons rigidlyconnected together s3 that they must always move in unison, and valvesso arranged that b-eing controlled by the movements of the pistons, theyprovide means for admitting fluid to and exhausting it from the brakecylinders,-

one ot' the pistons being exposed (on -the side next to the otherpiston) to a fluid pressure supplied from a storage reservoir or apressure reducing valve supplied from any suitable source; the otherside of the same piston being exposed to the pressure existing in thecontrolling chamber (or pipe), which is governed by a manually operatedValve 26, the details of construction of which will be hereinafterdescribed. The other piston (10) is exposed to brake cylinder pressureon the side next to the piston 9 and to atmospheric pressure on the oher side. As a result, the brake can be applied and the cylinderpressure maintained by a reduction of pressure in the controlling pipe2O and controlling or maintenance chamber 2, and in the normal (release)position of the mechanism, both pistons 9 and 10 will be balanced sothat there will be no undue wear or friction produced in the preliminaryapplication of the brake.

Assume now, that the pressures in the pipes 17 and 20 are equalized(viz. that the release is full) and that it is desired toput a certainamount of pressure in the brake cylinder 1L and to maintain that degreeof pressure notwithstanding any leakage which might occur from the brakecylinder; this may be accomplished by irst reducing the pressure in thepipe 20 to the proper point and then closing this pipe completely. Thenthe excess of pressure entering the chamber 2 by the duct 1G and pipe 17will cause an upward movement of the pistons 9 and 10 until the valve 14is pressed on its seat on the lower end of sleeve 12 by the spring 15,thus closing communication between duct 22 and chamber 13 (that is,closing the exhaust port). The upward movement of the pistons 9-10 willcontinue (the lower end of the rod 8 leaving the upper end of the stem11 of valve 14) until the valve 7 permits air entering the chamber 2 'bythe duct 1G, to iow from said chamber, through the chamber 6 in Vsleeve5 to the duct 21 and through said duct, to the brake cylinder 1a, untilthe pressure in said cylinder (which pressure, by reason of the duct 23,acts upon the upper side of the piston 10) is suHic'ient to overcome theopposing pressure on the piston 9. The pistons 9 and 10 will then movedownwardly until the valve 7 closes and thus prevent further ow of airfrom the duct 16 to the duct 21, and the stem of the valve 14 opposesthe further movement of the pistons because of the spring 15 and thecylinder pressure acting on the Valve 14. Now if the pressure in thebrake cylinder falls at all, the upward force acting against the piston9 will overcome the downward force acting on the piston 10 and the valve7 will again admit air to the duct 21 until the desired pressure is'again restored, thus positively maintaining cylinder pressures to anydesired point. By reducing the pressure in the pipe 2O and duct 19 to astill lower degree, the cylinder pressure will, of course, be increased.Should it be desired to release the cylinder pressure, it i's simplynecessary to increase the pressure in the pipe 20 and chiot 19, when thevalves will be caused to assume the position shown in Fig. 1 of thedrawing,-the release being then complete if vthe pressure in the pipe 20is fully restored, but only partial if the pressure in the pipe 2O isonly partially restored. Assuming that it is only partiallyrestored,-viz. that there is still a difference of pressure actingagainst the piston 9 tending` to force it upward,- when the pressure ofthe cylinder air acting on the piston 10 is no longer able to hold thevalve 7 in the position indicated, said valve will move upwardly untilthe valve 14 closes and the force exerted by the cylinder pressureacting on it and by the spring 15 no longer aids in this motion,-thusstopping the exhaust and retaining the desired amount of cylinderpressure.

The -manually operated controlling valve 2G, hereinbefore alluded to, isadapted to be moved to four positions, viz., release, lap, service, andemergency, and it also provides means for securing a higher brakecylinder pressure in emergency than service.

The controlling device 26 comprises a casing 27 having a valve seat 28provided with a series of ports a, b, c, cl, and on the seat 28 a rotaryvalve 29 is located. A spindle 30 mounted in the top 'of the casing,engages the valve 29, and to said spindle, an operating lever 31 issecured and provided with means `for retaining it in any position towhich it may be moved. The casing is provided with a duct 32 whichcommunicates at one end with a pipe 33 connected with the pipe 17 fromthe main source of fluid pressure supply. The other end of the ductr 32communicates Ywith a duct 34 over the valve 29, andthe last-mentionedduct communi- Cates with a 'passage 35 inthe Valve, which passage, undercertain conditions, is adapted `tain of the ports. The port acommunicates With a duct 42, which latter may be connected with a pipe(not shown) leading to a track sanding device, an alarm or other dev1ce.

Vhen the parts of the controlling device f 26, are in release position,as shown in Fig. 1, air will flow from the pipes 1733,

through ducts 32-34, passage 35, port Z and duct 36 to the pipe 37 andtrain pipe 20. Vhen the ports are in lap position, as shown in Fig. 4,all the ports are closed, thus permitting the operator to hold anyamount of pressure that has been attained in the train line pipe andconsequently a correspondingvdegree in the brake cylinder. In serviceposition, as shown in Fig. 5, the ports `c and l are connected by cavity41, thus permitting air to flow from pipe 20 to the atmosphere past thecheek valve 39", and through the chamber 38 and ducts 39. The maximumreduction possible in this position is, of course limited, by the checkvalve 39a and spring 40, to such a value that the corresponding cylinderpressure obtained Will be somewhat less than the maximum amount which itWould be possible to obtain from the source of supply through the pipe17. In emergency position, as shown in Fig. 6, the port d is connectedwith ports Z) and c, thus permitting of a complete and rapid exhaust ofpressure in pipes 37 and 20, with the result that the full pressurecarried in the supply pipe 17 Will be obtained in the brake cylinder.Then the ports are in the position shown in Fig. 6, a port 43 in thevalve will admit air to port a, which may be piped from the duct 42 totrack-sanding devices, or an alarm.

In the modified construction of the valve mechanism shown in Fig. 7, thevalve 7 is displaced by a slide valve 44 movable by the rod 8 in a valvechamber 45 which communicates at one end with the chamber 2. The slidevalve is adapted in one position) to connect the port or duct 21aleading to the brake cvlinder With the port 24*1 open to the atmosphere.In a different position of the valve 44, fluid Will flow from thechamber 45 to the brake cylinder, through a duct 45a in the valve, or inlarger quantity, past the end of said valve when the valve has beenmoved approximately to the end of its throw. A duct 23a conducts fluidfrom the duet 21a to the chamber 3 at one side of the piston 10, theother side of said chamber being open to. the atmosphere by a port 25a.Fluid pressure from the pipe 17 enters the valve chamber 45 at 46 andflows into the chamber 2 at one side of the piston 9, said chamber, atthe other side of the piston having communication through ducts 46 andchamber 47 with the train pipe 2O at 48. In this construction, a spring49 is provided, the resistance of which is added to the train pipepressure against the movement of the piston 8 during a portion of thethrow in one direction of the latter.

In the construction shown in Fig. 8, a spring 5() similar in locationand function to the spring 49 shown in Fig. 7, is employed. In Fig. 8,the chambers 2 and 3 and the pistons 9 and 10 are disposed in differentplanes, and the rods of these pistons are connected so that said pistonswill move together, through the medium of a pin 51 movable in a slot 52.A slide valve similar to the valve 44, in Fig. 7 is employed and adaptedto connect a chamber 54 with the exhaust duct 55. The chamber 54 is alsoconnected through a duct 56 with the chamber 3 and the latter isprovided at the other side of the piston 10 with a vent 57. The chamber54 also communicates, through the medium of a duct 54u with the brakecylinder passage. In a different position of valve 53 from that shown inthe drawing, the exhaust passage 55 will be closed and air permitted toflow from the valve chamber, through the slot 52, chamber 54 and duct 54to the brake cylinder. The main supply pipe 17 is connected at 58 andthe train pipe 20 is connected at 59, the same as in the constructionshovvn in Fig. 7.

In the construction shown in Fig. 9, a spring 58 similar in location andfunction as the springs 49 and 50 in Figs. 7 and 8, is employed, but inthe arrangement shown in Fig. 9, the main valve 7 l is similar' inlocation and operation to the main valve 7 shown in Fig. 1. Theconstruction shown in Fig. 9 also differs from that shown in Fig. 1, inthat the exhaust is controlled by the piston 10 which passes over ports59 communicating with the exhaust duct G0.

In addition to its functions .in assisting the closing ol valve 14,(Fig. 1), the spring 15 serves to add resistance to the movement of theconnected pistons, when the valve 7 has closed communication between thechamber 2 and the brake cylinder and before said valve has been fullyseated and before the exhaust valve 14 has been opened. Under theseconditions, passage of fluid from the brake cylinder will be preventedand a pressure less than the maximum pressure attainable, can bemaintained in the brake cylinder. The springs 49, Fig. 7 50 Fig. 8 and58 Fig. 9, Witll serve to prevent admission of air to the brakecylinder. In other words, the spring l5 tends to facilitate admissionand prevent eXhaust, while the' springs 49, 5() and 58, when active,limit admission and facili-tate the movement toward the exhaustposition.

Having fully described my invention what I claim as new and desire tosecure by Letters-Patent, is

l. In a valve mechanism, the combination with a casing having twochambers, of pistons in said chambers, means connecting said pistons andcausing them to move simultaneously, means for subjecting one of saidpistons on one side to pressure from a source of constant supply and onthe other side to train pipe pressure, means for subjecting` the otherpiston on one side to brake cylinder pressure and on the other side to adifferent pressure, a valve controlled by the movements of saidconnected pistons for controlling the passage of fluid from said sourceof constant supply to a brake cylinder, and means for controlling brakecylinder exhaust.

2. In a valve mechanism, the combination with a casing having twochambers, of pistons in said chambers, means connecting said pistons andcausing them to move simultaneously, means for subjecting one of saidpistons on one side to pressure from a source of constant supply and onthe other side to train pipe pressure, means for subjecting the otherpiston on one side to brake cylinder pressure and on the other side to adifferent pressure, a valve controlled by the movements of saidconnected pistons for controlling the passage of fluid from said sourceof constant supply to a brake cylinder, and means controlled by themovement of the connected pistons for opening and closing the brakecylinder exhaust.

3. In a valve mechanism, the combination with a casing having twochambers, of pistons in said chambers, means connecting said pistons andcausing them to move sii'nultaneously, means for subjecting one ot' saidpistons on one side to pressure from a source of constant supply and onthe other side to train pipe pressure, means for subjecting' the otherpiston on one side to brake cylinder pressure and on the other side to adifferent pressure, a valve controlled by the movements of saidconnected pistons for controlling the passage of fluid from said sourceof constant supply to a brake cylinder, a brake cylinder exhaust duct,and a valve operative by the movements of the connected pistons to openand close said duct.

4. In a valve mechanism, the combination with a casing' having twochambers, of pistons in said chambers, means connecting' g 'said pistonsand causing them to move sii multaneously, means for subjecting one ofsaid pistons on one 'side to pressure from a source of constant supplyand on the other side to train pipe pressure, means for subjecting theother piston on one side to brake cylinder pressure and on the otherside to a different pressure, a valve rcontrolled by the movements ofsaid connected pistons for controlling the passage of' supply fluid to abrake cylinder, an exhaust valve, means for subjecting said exhaustvalve to brake cylinder pressure, a spring tending to close saidexhausty valve, and means cooperating with the connected piston foropening said eX- haust valve.

The combination with a casing having two separated chambers, of pistonsin said chambers, means connecting said pistons and causing' them tomove simultaneously, av

liuid pressure supply from a maintained source and a train pipecommunicating with one of said chambers at respective sides of thepiston therein, a valve movable by said pistons to control the passageof liuid from said source of constant supply to a brake cylinder, meansfor subjecting the other piston on one side to brakecylinder pressureand on the other side to a different pressure, means for controllingbrake cylinder eX- haust, and a manually operated valve device forcontrolling fluid in the train pipe.

6. In a valve mechanism, the combination with a casing having twochambers, of pistons in said chambers, means connecting said pistons andcausing them to move simultaneously, means for subjecting one of saidpistons on one side to pressure from a source ot constant supply and onthe other side to train pipe pressure, means for subjecting' the otherpiston on one side to brake cylinder pressure and on the other side to adiliierent pressure, a valve controlled by the movements of theconnected pistons for controlling the passage of fluid from said sourceof constant supply to the brake cylinder, means for controlling thebrake cylinder exhaust, and means for varying the resistance to themovement of the connected pistons, whereby the passage of fluid to andfrom the brake cylinder can be prevented.

T. In a valve mechanism, the combination of a casing having twoseparated chambers, a piston in each of said chambers, connectionsbetween said pistons causing them to move simultaneously, a valveoperated by said connections` meansy for admitting fluid from a sourceof constant supply t0 one of said chambers at one side of the pistontherein, means for admitting train pipe fluid to the same chamber at theother side of the piston, means controlled by said valve for controllingpassage of fluid from said source of constant' supply to a brakecylinder, means for admitting fluid ofdifl'erent pressures to the otherchamber at respective sides of the piston thereon and means forexhausting brake cylinder fluid.

8. In a valve mechanism, the combination with a casing having tWoseparated chambers, of pistons in said chambers, connecting meansbetween said pistons, a fluid supply duct and a train pipe ductcommunicating with one of said chambers at respective sides of thepiston therein, means for conducting fluid from a source of constantsupply to said iuid supply duct, a brake cylinder duct, a valvecontrolled by the movements of said pistons for controlling the passageof iuid from said source of constant supply to 15 means for subjectingsaid piston on its other 20 side to a different pressure.

In testimony whereof, I have signed this specification in the presenceof two subscribing Witnesses. l

HO/VARD M. P. MURPHY.

Vi tnesses R. S. FERGUSON, A. WV. BRIGHT.

